Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. Interleukin-2 may stimulate a person's white blood cells to kill cancer cells. Combining rituximab with interleukin-2 may kill more cancer cells. Phase I trial to study the effectiveness of rituximab plus interleukin-2 in treating patients who have hematologic cancer.